SEATTLE — Fueled by its deafening home crowd, the Seattle Seahawks locked up their spot in the postseason Sunday night.

They also reinforced the notion no one in the NFC wants to see them when the playoffs begin, even if they are a wild card.

Russell Wilson threw a career high four touchdown passes to move into second place for most TD passes by a rookie. Marshawn Lynch scored two first-quarter TDs, and the Seahawks blew out the San Francisco 49ers 42-13.

Richard Sherman returned a blocked field goal 90 yards for another touchdown as the Seahawks (10-5) jumped to a 21-0 lead. That only added to an already hyped crowd on a typically cold and rainy December night, with noise echoing off the walls and overhanging roof of CenturyLink Field that might have been heard all the way across Puget Sound.

No one cared about the cold rain. Not with the performance they were seeing on the field. And not with a ticket to the postseason guaranteed thanks to Seattle's first 10-win season since 2007.

Most likely Seattle will be the No. 5 seed in the NFC. There remains a slight chance of winning the NFC West if the Seahawks beat St. Louis in the season finale and Arizona can upset the 49ers in San Francisco.

The Seahawks, 7-0 at home, delayed San Francisco (10-4-1) from celebrating a division title on Seattle's turf. They turned Jim Harbaugh's 49th birthday into a miserable, wet evening.

Whether home or road, the Seahawks are a scary postseason opponent with the way they are playing.

Seattle was the first team since 1950 to score at least 50 points in consecutive weeks thanks to its 58-0 win over Arizona and 50-17 victory against Buffalo. It seemed inconceivable the scoring binge could continue against San Francisco, the best scoring defense in the NFL.